The present invention relates to a method for producing a twisted yarn by an integrated spinning and twisting process according to the two-for-one principle wherein with two adjacently positioned spinning devices individual spun yarns are produced which are combined and then subjected to a common twisting process and, subsequently, are then guided in the opposite direction, according to the two-for-one principle, under formation of a yarn balloon rotating about the spinning devices to a centering point above the spinning devices and to a winding device. Each spinning device is supplied with loose fiber material fed in a substantially radial direction through the yarn balloon. The fiber material is first guided in the radial direction to an annular chamber extending coaxially to the axis of the yarn balloon in which the yarn balloon is guided. Subsequently, the loose fiber material is guided under the effect of a pressure gradient in a substantially radial direction out of the annular chamber and to the spinning devices. The corresponding device has the aforementioned structural features.
Such a device and method are known from German Patent application 44 27 875.
In the method and device known from this publication, the loose fiber material is first guided via fiber feed channels to an annular chamber that is arranged coaxially to the spindle axis. The yarn forming the yarn balloon is guided through this annular chamber such that it rotates through the annular chamber within a column or spoke that is part of the rotating component so that the yarn forming the yarn balloon does not come into direct contact with the supplied fiber material. This construction is based on the prejudice that the fiber stream and the rotating yarn should not interfere with one another. The column or spoke though which the yarn is guided can be designed such that no fibers will attach to it. In one embodiment for performing this invention, the rotating component which comprises the yarn guide element, in which the yarn is guided within the yarn balloon, is embodied as a pot that is fixedly connected to the spindle rotor. It has at its upper end two annular components positioned opposite one another in the axial direction which delimit therebetween the annular chamber. The two annular parts are connected to one another by spoke-like connecting elements which penetrate the annular chamber whereby the yarn guide element is arranged in one of the connecting elements.
In principle, such a connecting element containing the yarn guide element at the circumference of the pot would be sufficient for guiding the yarn through the annular chamber. However, this is disadvantageous with regard to machine-technological considerations because of the resulting imbalance. It is therefore more desirable to have at least two, preferably three, such spoke-like connecting elements distributed about the circumference. However, this has the consequence that the fiber stream for each spindle rotation would be subjected to three disruptions. Since the connecting elements, because of constructive reasons, have a certain minimum width in the circumferential direction, even for a flow-technologically optimized contour of the connecting elements, individual fibers will be removed from the fiber stream and a fiber disorientation will result.
Furthermore, it has been shown that the connecting elements between the annular parts of the pot are also a source of high noise emission. They act, despite advantageous flow contours, like a siren whose sound, despite an encapsulated embodiment, still penetrates to the exterior with an unacceptable noise level.
It is therefore an object of the present invention to embody a method and a device of the aforementioned kind such that during supply of the fiber material a minimal fiber disorientation will result and the noise emission is considerably reduced.